My last puzzle/riddle was far too easy, so here is a more difficult one.

Decypher this:

PULU SI BAGUMBA

What does it mean? Does anyone know?
Hint: this isn't another Caesar cypher.

☺

It's from an old show called 'Gilligan's Island'.

[media=https://www.youtube.com/watch?v=7J9mjOd1NHs]